On the latter, I smoothed the curves and closed off all the volumes. It is probably printable now. But there's more work to go to make it a hollow object with holes for bolts and functional handle and so forth.
The hand truck was simpler; the bearing on one wheel failed under load and the stuck wheel got hot enough to tear a hole in the plastic supports. So I drilled out a 3/8" hole in the supports, and seated a bronze bushing in a cylinder of aluminium I lathed down to make a replacement hub, and secured a bolt through the new bearing. Was the first time I used a boring bit on the lathe, too.
I've ordered most of the material and parts for the Raygun now. The CAD file still has a lot of work to go, though. Holocron is even further...finishing the Inkscape files won't take quite as long, but I need to drive across town for more acrylic stock. Pity. There's interest in a cheap holocron kit at the RPF. Unfortunately I'm also shooting for a unit price that is barely greater than cost.
And both projects look to need me to spend more time at my DuckNode. Which isn't just PCB layout time -- I need to pull out the breadboard and experiment to see how to enhance the stability of the circuit under full load.